The European agency routinely conducts pharmacovigilance inspections to ensure drug companies are correctly reporting incidents, said Reuters. MHRA has discussed the situation with the FDA and said it identified the problems after an inspection conducted at Roche as part of a collaborative European program that reviews drug safety reporting systems, said Dow Jones.

The review revealed that Roche never appropriately evaluated about 80,000 reports associated with a Roche-sponsored financial patient reimbursement support program in the United States to determine if the reports should be treated as suspected adverse reactions. Of the 80,000 reports, 15,161 involved patient deaths. The Roche-sponsored U.S. Patient Reimbursement Program, set up by Roche’s Genentech unit, goes back to 1997, said Reuters.

Reuters explained that the medicines involved span Roche’s product range, noting that Roche is the world’s largest maker of cancer medicines, but also manufactures drugs for viral infections, central nervous system disorders, and inflammatory diseases.

“It is not known whether the deaths were due to natural progression of the disease or had a causal link to the medicine. More recent information from the company indicates a smaller number of reports, but this information needs to be verified by the authorities,” Roche said in a statement.

The agency does not believe evidence exists that there is currently a negative impact to patients, saying in a statement that, “There is, at present, no evidence of a negative impact for patients, and while the investigations are being conducted there is no need for patients or healthcare professionals to take any action,” according to Reuters.

Roche did acknowledge to not fully complying with safety reporting regulations and said it will be rectifying the matter, noting that “The non-reporting of these potentially missed adverse events was not intentional and the company is working closely with health authorities, including the European Medicines Agency, to implement these measures in due time,” said Dow Jones citing Roche’s statement. “Based on Roche’s assessments, to date, no impact on the safety profile of any of its products has been found,” Roche added.

A spokesman for the drug maker said it plans on providing a final assessment of the number of possibly missed adverse events to health authorities no later than January 2013, said Reuters.

Meanwhile, said Reuters, MHRA discovered other deficiencies at Roche concerning the reporting of 23,000 potential adverse reaction reports to national medicines agencies, as well as another 600 incidents concerning patients in clinical trials.